If you no longer wish to use your SwiftKey Account, or would like to change the account associated with SwiftKey Account, then you can do so by following these steps:
- Open the SwiftKey app from your device
- Tap 'Account'
- Tap ‘Delete SwiftKey Account'
- Select ‘Delete’
Please note that this will unregister all of your connected devices, and also delete your backed-up data from your SwiftKey Account.